private Maps() {}

  private enum EntryFunction implements Function<Entry<?, ?>, @Nullable Object> {
    KEY {
      @Override
      @CheckForNull
      public Object apply(Entry<?, ?> entry) {
        return entry.getKey();
      }
    },
    VALUE {
      @Override
      @CheckForNull
      public Object apply(Entry<?, ?> entry) {
        return entry.getValue();
      }
    };
  }

    map.put("bar", 3);
    Iterator<Entry<String, Integer>> entries = map.entries().iterator();
    Entry<String, Integer> entry = entries.next();
    assertEquals("bar", entry.getKey());
    assertEquals(1, (int) entry.getValue());
    entry = entries.next();
    assertEquals("foo", entry.getKey());
    assertEquals(2, (int) entry.getValue());
    entry.setValue(4);
    entry = entries.next();

    @Override
    protected BiMap<String, String> create(Entry<String, String>[] entries) {
      ImmutableBiMap.Builder<String, String> builder = ImmutableBiMap.builder();
      for (Entry<String, String> entry : entries) {
        checkNotNull(entry);
        builder.put(entry.getKey(), entry.getValue());
      }
      return builder.build();
    }
  }

    private static Entry<TypeToken, Object> entry(TypeToken<?> k, Object v) {
      return immutableEntry((TypeToken) k, v);
    }

    @Override
    @SuppressWarnings("unchecked")
    public Entry<TypeToken, Object>[] createArray(int length) {
      return (Entry<TypeToken, Object>[]) new Entry<?, ?>[length];
    }

    @Override
    public Iterable<Entry<TypeToken, Object>> order(List<Entry<TypeToken, Object>> insertionOrder) {

    @SuppressWarnings("unchecked")
    Entry<String, String>[] array = (Entry<String, String>[]) new Entry<?, ?>[entries.length];
    int i = 0;
    for (Object o : entries) {
      @SuppressWarnings("unchecked")
      Entry<String, String> e = (Entry<String, String>) o;
      array[i++] = e;
    }
    return create(array);
  }

  protected abstract Map<String, String> create(Entry<String, String>[] entries);

  @Override

  @Override
  public Set<Entry<K, V>> create(Object... elements) {
    Entry<K, V>[] entries = createArray(elements.length);
    arraycopy(elements, 0, entries, 0, elements.length);
    return createFromEntries(entries);
  }

  public abstract Set<Entry<K, V>> createFromEntries(Entry<K, V>[] entries);

  @Override
  @SuppressWarnings("unchecked") // generic arrays make typesafety sad
  public Entry<K, V>[] createArray(int length) {

            }
            return size;
        }
        if (obj instanceof Map<?, ?>) {
            long size = 0;
            for (final Map.Entry<?, ?> entry : ((Map<?, ?>) obj).entrySet()) {
                size += sizeOf(entry.getKey());
                size += sizeOf(entry.getValue());
            }
            return size;
        }
        return 16L;
    }

  private Entry<K, V> nullKeyEntry;
  private Entry<K, V> nullValueEntry;
  private Entry<K, V> nullKeyValueEntry;
  private Entry<K, V> presentKeyNullValueEntry;

  @Override
  public void setUp() throws Exception {
    super.setUp();
    nullKeyEntry = entry(null, v3());
    nullValueEntry = entry(k3(), null);
    nullKeyValueEntry = entry(null, null);

  }

  private Entry<K, V>[] getEntriesMultipleNullKeys() {
    Entry<K, V>[] entries = createArrayWithNullKey();
    entries[0] = entry(null, entries[0].getValue());
    return entries;
  }

  private Entry<K, V>[] getEntriesMultipleNonNullKeys() {
    Entry<K, V>[] entries = createSamplesArray();
    entries[0] = entry(k1(), v0());
    return entries;
  }

  }

  private static <K, V> Map<K, V> newHashMap(
      Collection<? extends Entry<? extends K, ? extends V>> entries) {
    HashMap<K, V> map = new HashMap<>();
    for (Entry<? extends K, ? extends V> entry : entries) {
      map.put(entry.getKey(), entry.getValue());
    }
    return map;
  }